/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.table.functions.hive.util;

import org.apache.flink.annotation.Internal;
import org.apache.flink.table.functions.hive.FlinkHiveUDFException;
import org.apache.flink.table.types.DataType;
import org.apache.flink.table.types.logical.ArrayType;
import org.apache.flink.table.types.logical.LogicalType;
import org.apache.flink.table.types.logical.LogicalTypeRoot;

/**
 * Util for Hive functions.
 */
@Internal
public class HiveFunctionUtil {
	public static boolean isSingleBoxedArray(DataType[] argTypes) {
		for (DataType dataType : argTypes) {
			if (HiveFunctionUtil.isPrimitiveArray(dataType)) {
				throw new FlinkHiveUDFException("Flink doesn't support primitive array for Hive functions yet.");
			}
		}

		return argTypes.length == 1 && HiveFunctionUtil.isArrayType(argTypes[0]);
	}

	private static boolean isPrimitiveArray(DataType dataType) {
		if (isArrayType(dataType)) {
			ArrayType arrayType = (ArrayType) dataType.getLogicalType();

			LogicalType elementType = arrayType.getElementType();
			return !(elementType.isNullable() || !isPrimitive(elementType));
		} else {
			return false;
		}
	}

	// This is copied from PlannerTypeUtils in flink-table-runtime-blink that we shouldn't depend on
	// TODO: remove this and use the original code when it's moved to accessible, dependable module
	private static boolean isPrimitive(LogicalType type) {
		switch (type.getTypeRoot()) {
			case BOOLEAN:
			case TINYINT:
			case SMALLINT:
			case INTEGER:
			case BIGINT:
			case FLOAT:
			case DOUBLE:
				return true;
			default:
				return false;
		}
	}

	private static boolean isArrayType(DataType dataType) {
		return dataType.getLogicalType().getTypeRoot().equals(LogicalTypeRoot.ARRAY);
	}
}
